here is the deck i use for lvl 40 yugi. 7k+ assessment. i have a cerberus deck made up but its risky if you don't draw riryoku field early on and he draws OTC before you get riryoku field. so this is safer than cerberus.
yes. consistent enough for me. haven't failed a single duel except the first time i used it and had a glitch on using temple effect to summon ultimate blue eyes. they fixed it now though so it's all good.
the double summon is not really necessary for the deck to run smooth. you can replace it with any spell you want, it's just there for safety precaution just in case your last card would be either Serket or Temple, then you would have to use double summon but otherwise you don't need to. i usually summon serket when i have 1 card left in deck. Piranha on last turn.